Nonlocal growth of quantum conditional mutual information under decoherence

Fuente: arXiv
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Auteurs principaux: Zhang, Yifan, Gopalakrishnan, Sarang
Format: Preprint
Publié: 2024
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author Zhang, Yifan
Gopalakrishnan, Sarang
author_facet Zhang, Yifan
Gopalakrishnan, Sarang
contents Local measurements cannot create entanglement, but they can convert short-range entanglement to long-range entanglement, as in quantum teleportation. This phenomenon of measurement-induced entanglement (MIE) has been widely discussed in recent work on measurement-induced entanglement phase transitions and related phenomena. Here, we situate MIE in a broader context of the growth of long-range conditional mutual information (CMI) under decoherence. We upper-bound the rate at which decoherence can generate long-range CMI, and derive a characterization of states that saturate this bound. We point out that the structure of states saturating the CMI upper bound can be very different under different decoherent dynamics and provide explicit examples. We additionally explore the dynamics of CMI in random quantum circuits subject to random local decoherence, as a function of circuit depth. We argue that the universality class of the finite-depth teleportation transition, as well as its lower critical dimension, are different for erasures than for measurements.
format Preprint
id arxiv_https___arxiv_org_abs_2402_03439
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Nonlocal growth of quantum conditional mutual information under decoherence
Zhang, Yifan
Gopalakrishnan, Sarang
Quantum Physics
Statistical Mechanics
Strongly Correlated Electrons
Local measurements cannot create entanglement, but they can convert short-range entanglement to long-range entanglement, as in quantum teleportation. This phenomenon of measurement-induced entanglement (MIE) has been widely discussed in recent work on measurement-induced entanglement phase transitions and related phenomena. Here, we situate MIE in a broader context of the growth of long-range conditional mutual information (CMI) under decoherence. We upper-bound the rate at which decoherence can generate long-range CMI, and derive a characterization of states that saturate this bound. We point out that the structure of states saturating the CMI upper bound can be very different under different decoherent dynamics and provide explicit examples. We additionally explore the dynamics of CMI in random quantum circuits subject to random local decoherence, as a function of circuit depth. We argue that the universality class of the finite-depth teleportation transition, as well as its lower critical dimension, are different for erasures than for measurements.
title Nonlocal growth of quantum conditional mutual information under decoherence
topic Quantum Physics
Statistical Mechanics
Strongly Correlated Electrons
url https://arxiv.org/abs/2402.03439